random-util: add common helper random_write_entropy() for crediting entropy to the kernel's pool

1 files changed, 3 insertions, 17 deletions

diff --git a/src/core/efi-random.c b/src/core/efi-random.c
index c4d25d68e4..b6609e63e5 100644
--- a/src/core/efi-random.c
+++ b/src/core/efi-random.c
@@ -1,8 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
 #include <fcntl.h>
-#include <linux/random.h>
-#include <sys/ioctl.h>
 #include <unistd.h>
 
 #include "alloc-util.h"
@@ -11,6 +9,7 @@
 #include "efivars.h"
 #include "fd-util.h"
 #include "fs-util.h"
+#include "random-util.h"
 #include "strv.h"
 
 /* If a random seed was passed by the boot loader in the LoaderRandomSeed EFI variable, let's credit it to
@@ -43,7 +42,6 @@ static void lock_down_efi_variables(void) {
 }
 
 int efi_take_random_seed(void) {
-        _cleanup_free_ struct rand_pool_info *info = NULL;
         _cleanup_free_ void *value = NULL;
         _cleanup_close_ int random_fd = -1;
         size_t size;
@@ -79,11 +77,6 @@ int efi_take_random_seed(void) {
         if (size == 0)
                 return log_warning_errno(SYNTHETIC_ERRNO(EINVAL), "Random seed passed from boot loader has zero size? Ignoring.");
 
-        /* The kernel API only accepts "int" as entropy count (which is in bits), let's avoid any chance for
-         * confusion here. */
-        if (size > INT_MAX / 8)
-                size = INT_MAX / 8;
-
         random_fd = open("/dev/urandom", O_WRONLY|O_CLOEXEC|O_NOCTTY);
         if (random_fd < 0)
                 return log_warning_errno(errno, "Failed to open /dev/urandom for writing, ignoring: %m");
@@ -94,15 +87,8 @@ int efi_take_random_seed(void) {
         if (r < 0)
                 return log_warning_errno(r, "Unable to mark EFI random seed as used, not using it: %m");
 
-        info = malloc(offsetof(struct rand_pool_info, buf) + size);
-        if (!info)
-                return log_oom();
-
-        info->entropy_count = size * 8;
-        info->buf_size = size;
-        memcpy(info->buf, value, size);
-
-        if (ioctl(random_fd, RNDADDENTROPY, info) < 0)
+        r = random_write_entropy(random_fd, value, size, true);
+        if (r < 0)
                 return log_warning_errno(errno, "Failed to credit entropy, ignoring: %m");
 
         log_info("Successfully credited entropy passed from boot loader.");